:
The study protocol was approved by the IRB (ethics committee of the University of Rostock): Reg.-No.: A 2017–0148. Written informed consent was obtained from all participants.

:
JS reported of no conflict of interest. AP reported of no conflict of interest. MB reported of no conflict of interest. ÄG reported of no conflict of interest. BG reported of no conflict of interest.

:
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.